/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.hadoop.hive.common;

/** Simple object pool to prevent GC on small objects passed between threads. */
public interface Pool<T> {
  /** Object helper for objects stored in the pool. */
  public interface PoolObjectHelper<T> {
    /** Called to create an object when one cannot be provided.
     * @return a newly allocated object
     */
    T create();
    /** Called before the object is put in the pool (regardless of whether put succeeds).
     * @param t the object to reset
     */
    void resetBeforeOffer(T t);
  }

  T take();
  void offer(T t);
  int size();
}